The effect of high temperature (up to 1120°C)-high pressure (up to 1.1 GPa) treatment on the resulting defect structure of preannealed (450-725°C, up to 96 hours) Czochralski grown Si crystals was studied by X-ray diffraction. The values of the Debye-Waller static factor and of the root-mean-square atomic displacement due to defects were determined for various Lane reflections. Well-defined development of the cluster like defect structure after high temperature pressurization depending to a substantial extent on the preannealing conditions was observed.
Sensitivity of X-ray integral reflectivity of GaAs single crystal to a degree of structure distortions was established to grow considerably in the Bragg diffraction case when the characteristic AgK_{α_{1}} line is changed for more hard white radiation. In effect, the absorption length essentially exceeds the extinction length what results in enhancement of incoherent scattering. Measurements of X-ray integral reflectivity coordinate dependence by single crystal spectrometer permitted to determine the mean level of crystal lattice distortion as well as the degree of structure homogeneity of a sample with dislocations. The Debye-Waller static factor value was estimated from X-ray integral reflectivity magnitudes for the 800 reflection of white radiation.
High-purity n-type GaAs crystal was grown by the Synthesis, Solute Diffusion (SSD) method. Deep Level Transient Spectroscopy (DLTS) characterization of the crystal revealed three deep traps related to native defects. Microscopic origin of the traps is discussed and prospective use of SSD-grown GaAs as a bulk material with the high luminescence efficiency is emphasized.
The interaction between impurities of two solute elements in metal hosts leads to a non-random distribution of impurity atoms among the lattice sites. Experimental studies of this distribution provide quantitative information on the energy involved in the formation of an individual impurity-impurity pair. The perturbed angular correlation measurements performed with ^{111}In probe atoms and Mössbauer spectra of ^{57}Co are used to derive the interaction energy of In atoms with Mn and Co atoms introduced into silver matrix. It is demonstrated that In atoms attract Mn and Co atoms and in the case of In-Mn pair the interaction energy value was determined. The obtained results are discussed in the frame of the semiempirical model and the recent first principles theoretical calculations.
A survey is presented of the structure, stability, and reorientation kinetics of acceptor-H and donor-H complexes in Si and III-V semiconductors. A few examples of the unintentional introduction of H into device materials are also discussed.
Strong electric-field enhancement of the thermal emission rate of holes from the doubly ionized charge state of the EL2 defect was revealed with the deep-level transient spectroscopy in p-type GaAs and analyzed in a model of phonon-assisted tunnel effect. Similar dependence observed for the electric field directions parallel to three main crystallographic axes suggests tetrahedral symmetry of the defect which is consistent with its identification as the arsenic antisite.
Experimental results are presented confirming that the two energy levels in GaAs: E_{c} - 0.68 eV and E_{v} + 0.37 eV, discovered in plastically deformed crystals, belong actually to dislocations. In view of recent identification of the electron state of misfit dislocations at an InGaAs/GaAs interface, a correspondence between these levels and dislocation types has been reinterpreted. The first mentioned leve1 belongs likely to α while the second one to β dislocations of 60° (glide set) type. Such a correspondence is compatible with the observed effect of irradiation on dislocation glide motion in GaAs. It is also argued that these energy levels are involved in the phenomenon of unquenchability of the EL2 defects placed in high-stress regions near dislocations.
Bragg-case synchrotron section topographs were studied in parallel slabs cut from a synthetic diamond of a good quality. The topographs revealed the Pendellösung fringes and images of dislocations and other defects containing several fringe systems. The experiment provided the opportunity for studying of the theoretical dislocation images obtained by numerical integration of the Takagi-Taupin equations. A program employing a variable step of integration in the Bragg-case has been presented. The influence of the finite slit width and of the limited beam divergence on the theoretical images is also discussed.
Bragg-case synchrotron double-crystal images of stacking faults were studied in a slab prepared from a synthetic diamond of a good quality. The images of stacking faults in topographs taken on the tails of the rocking curve exhibited well pronounced interference fringes. The fringes were strongly dependent on the angular setting and they were less spaced further from the maximum. The experimental images were compared with those theoretically predicted from an application of plane-wave dynamical theory. A reasonably good correspondence between theoretical and experimental images was obtained. The theoretical images of stacking faults were dependent on the type of stacking fault, producing some difference in the first fringe.
The effect of hydrostatic pressure on some properties of Cz-Si with oxygen precipitates is investigated. The observed phenomena are discussed in terms of misfit between the precipitates and Si matrix.
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